This project is concerned with the dispersal of fungal spores in the indoor environment. At a time of widespread concern about microbial contamination of buildings, this project is motivated by the following questions: What mechanisms cause and maximize spore release in indoor fungi and what practices might help to minimize spore release? There are two specific experimental aims. Aim 1 is designed to elucidate mechanisms of spore release in indoor fungi. Despite the ubiquity of other fungi in the indoor environment, and their proven allergenic potential, we know little about their mechanisms of spore release. A combination of video microscopy and biomechanical techniques will be used to understand how the commonest indoor molds (sexual ascomycetes), sexual ascomycetes (that release ascospores), and basidiomycetes achieve spore release. Building upon the information gathered through the experiments of Aim 1, the experiments of Aim 2 will explore the environmental conditions (particularly humidity and airflow) that control spore release for each category of release mechanism. Fungal proliferation is almost inevitable following water intrusion into buildings, but unless spores become airborne, contamination will have little effect upon air quality. This means that controlling spore release may be an effective way to maintain air quality even in cases of severe building contamination. Furthermore, by focusing upon spore release rather than fungal growth it may be possible to reduce the use of potentially-hazardous chemicals during mold remediation efforts.